Cutting and Storing Brownies
After you cut the brownies, either cover the pan tightly with aluminum foil or remove the brownies and place them in an airtight container. If they contain perishable ingredients such as cream cheese, place them in the refrigerator. At room temperature, they’ll keep for three to four days; in the refrigerator, about five days.
Freezing brownies may affect their texture, so it’s best to take a few precautions. If the brownies have been cut into squares, wrap each square in plastic wrap, then in foil, and then place the wrapped squares in an airtight freezer bag.
Alternatively, you can freeze the whole pan briefly—just long enough to harden the brownies. Then remove the brownie “block,” wrap it tightly in plastic wrap, then in foil. Place the block into a large airtight freezer bag and freeze.
Pastry chef and chocolate expert Alice Medrich, who has written several books about baking with chocolate, swears by something she calls the “Steve ritual,” after a friend who discovered the technique by accident. She bakes her brownies for a shorter time at a higher temperature (375 to 400 degrees), then placing the hot pan in ice water about ¾" deep. The sudden change in temperature produces a crisp crust and a soft, dense center.